OrderFlow: Resilient .NET API & Angular Operations UI

OrderFlow — Resilient .NET API with Angular Operations UI

A self-directed full-stack portfolio case study showing how I design reliable backend workflows and turn them into a clear product experience.

THE CHALLENGE

Order creation is exposed to network retries, duplicate submissions, concurrent updates, and invalid state transitions. The UI must make those rules understandable without hiding offline or demo data.

BACKEND ENGINEERING

• .NET 10, C# 14, and ASP.NET Core Minimal APIs. • Atomic idempotent creation with replay and conflict handling. • Explicit Received → Processing → Completed workflow rules. • Optimistic concurrency, validation, RFC 7807 problem details, filtering, and pagination. • OpenAPI, health checks, correlation IDs, automated tests, GitHub Actions CI, and non-root Docker delivery.

ANGULAR PRODUCT UI

• Angular 22 and strict TypeScript with standalone components, signals, computed state, reactive forms, and typed HttpClient. • Order creation, safe retries, filters, metrics, and only the actions allowed by the current API state. • Accessible controls and clearly labelled offline/demo fallback.

DELIVERABLES

Public API and Angular repositories, automated tests, CI, Docker configuration, OpenAPI contract, and a live frontend demo.

API: https://github.com/leo8190/orderflow-api Frontend: https://github.com/leo8190/ops-dashboard